Upward acting or vertical opening sectional doors are ubiquitous as residential garage doors and are also widely used in commercial door applications. As part of a continuing need to provide improvements in sectional doors of the general type referenced herein, one pressing need has been to reduce the weight of the door while not sacrificing strength and rigidity and to provide a suitable secure closure over the door opening, such as a garage vehicle entry. In this regard, extrudable or moldable polymer materials have been given consideration for use in the main structural members of sectional garage doors and the like.
A problem associated with providing lightweight doors constructed of polymer materials has been the provision of suitable brackets and reinforcing members for transferring loads from counterbalance cables to the door structure itself. Moreover, such brackets, if connected to counterbalance cables, should be arranged in a way to minimize inadvertent disconnection of the bracket when the counterbalance cable is under tension to minimize the chance of injury, damage to the door structure and/or damage to the counterbalance mechanism.
Accordingly, with respect to doors manufactured of lightweight polymer materials, in particular, there has been a need to provide an improved bracket arrangement for connecting the counterbalance cable to the lower corner of the lower door section, which bracket is constructed and secured to the door in such a way as to minimize unwanted disconnection of the bracket. There has also been a need to provide a bracket which is further constructed in such a way as to assist in transferring forces exerted by counterbalance or operating cables to the door structure without imposing damaging stresses on the door structure. It is to these ends that the present invention has been developed.